Rotary pump and motor hydraulic transmission



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IN V EN TOR. CL IN TON M. WEL Ch,

c. M. WELCH 2,658,344

ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSION Nov. 10, 1953 Filed June 10, 1952 9 Sheets-Sheet 2 F/ G. .1? B.

. INVENTOR.

CLINTON .M. WELCH,

Nov. 10, 1953 c. M. WELCH 2,658,344

ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSION Filed June 10, 1952 I 9 Shets-Sheet 4 I 73:54 w w nvvuvrpn cu/vrzw M. W540,

Nov. 10, 1953 c. M. WELCH 2,653,344

ROTARY PUMP AND MQTOR HYDRAULIC TRANSMISSION Filed June 10, 1952 9 Sheets-Sheet 5 -.g.-:- J:: :33 Q ///X//////////////////V////////////I/W M Md a I INVENTOR.

CLINTON M. WELC/vj A 7' TWA/E Ys.

Nov. 10, 1953 c. M. WELCH 2,658,344

- ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSION Filed June 10, 1952 9 Sheets-Sheet 6 m 05 g /9Z Z be M5 INVENTOR. 62 m m M. W54 CH,

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ROTARY PUMP AND MOTOR HYDRAULIC TR'A NSMISSION I Filed June 10, 1952 9 Sheets-Sheet 7 7 u g 5 N D g INVENTOR. Q]. U cu/v r'o/v M. WEL cw,

E -BY Nov. 10, 1953 c. M. WELCH 2,658,344

ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSION Filed June 10', 1952 9 Sheets-Sheet 8 llflllllllllll I 9 Sheets-Sheet 9 F/ G. .12. ,57, m M 7 Ma c. M. WELCH ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSION Nov. 10, 1953 Filed June 10, 1952 INVENTOR. ('4 av ro/v M. W54 CH,

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Patented Nov. 10, 1953 UNITED STATES PATENT OFFICE ROTARY PUMP AND MOTOR HYDRAULIC TRANSMISSION This invention relates to hydraulic power transmissions and more particularly to a transmission for connecting a power source, such as an automotive vehicle engine, to power driven means, such as the traction wheels of the vehicle. and automatically adjusting the speed and torque factors of the power delivered to the driven means in accordance with variations in the load on the driven means.

It is among the objects of the invention to provide an improved hydraulic transmission of unitary construction which can be easily mounted on a suitable support, such as the frame of an automotive vehicle, and drivingly connected between a power source, such as a vehicle engine, and a driven means, such as a vehicle propeller shaft or differential unit connected in turn to the traction wheels of the vehicle; which is eifective to vary the torque and speed factors of the power delivered to the driven means in accordance with variations in the load on the driven means to increase the torque and reduce the speed as the torque of the load on the driven means increases and reduce the torque and increase the speed as the torque on the driven means decreases; which includes means for limiting the transmitted power to a predetermined value without stopping the transmission; which utilizes variations in the pressure of the hydraulic fluid in the transmission to adjust the speed and torque factors of the output power to maintain the output power substantially equal to the input power and includes means providing counter-balancing fluid pressure to maintain the adjustment against further change until a change in input or output power occurs; which provides means retaining the hydraulic fluid in the transmission against leakage; which includes vane type hydraulic pump and motor devices, the vanes of which are positively controlled to provide silent, wear-free operation and substantially preclude leakage of hydraulic fluid past the vanes; which has all parts requiring servicing or adjustment arranged for ready accessibility; which is manually changed between its operative and its inoperative conditions and does not absorb or transmit power when in its inoperative condition; which is reversible in operation, so that power can be transmitted therethrough in either direction; and which is simple and durable in construction, practical and economical to manufacture, easy to install, and positive and efficient in operation.

Other objects and advantages will become apparent from a consideration 0. .5 fill? IOHQWin description and the appended claims in conjunction with theaccompanying drawings wherein:

Figures 1A and 13 together constitute a medial, longitudinal cross sectional view of a hydraulic transmission illustrative of the invention;

Figure 2A is a transverse cross sectional view on the line 2A-2A of Figure 1A;

Figure 2B is a transverse cross sectional view on the line 2B-2B of Figure 1B;

Figure 3A is a transverse cross sectional view on the line 3A3A of Figure 1A;

Figure 3B is a transverse cross sectional view on the line 33-33 of Figure 1B;

Figure 4A is a transverse cross sectional view on the line 4A--4A of Figure 1A;

Figure 4B is a transverse cross sectional view on the line 4B-4B of Figure 1B;

Figure 5 is a transverse cross sectional view on the line 5-5 of Figure 1A;

Figure 6 is a fragmentary transverse cross sectional view on the line 66 of Figures 1A and 1B;

Figure 7 is a longitudinal cross sectional view on the line 1-1 of Figure 1A;

Figure 8 is a longitudinal cross sectional view on the line 8-8 of Figure 1A;

Figure 9 is a cross sectional view on the line 99 of Figure 2B;

Figure 10 is a cross sectional view on the line I 0-l 0 of Figure 2B;

Figure 11 is a fragmentary cross sectional view in the plane of the cross section of Figure 1B, being a sectional view on the line ll-ll of Figure 13, showing a somewhat modified form of the device;

Figure 12 is a cross sectional view on the line l2l2 of Figure 11;

Figure 13 is a cross sectional view on the line -l3|3 of Figure 11; and

Figure 14 is a perspective view of a hydraulic motor partition member as shown in Figure 13.

With continued reference to the drawings, the numeral [0 generally indicates the transmission housing which is formed in three separable parts including two end sections as designated at IA and [0B and an intermediate or center section HIC. The end sections [0A and IOB are of substantially rectangular shape and are recessed in their abutting faces to provide a cavity ll of elongated, rectangular shape which receives the inner section IOC which is of elongated, rectangular shape to fit and completely fill the cavity I I provided in the end sections. One end portion of the section I DA extends past an end of the cavity, as indicated at l2, to the abutting face of the section I63 and this extension I2 is provided with bolt extensions I3 which extend through bolt holes I4 in the corresponding portion of the section I6B and receives nuts I5 which clamp the end sections together at the corresponding end of the housing. At the other end of the housing the end section I6B has an end extension I6 which extends past the adjacent end of the center section I6C of the housing and is provided at its distal end with bolt ex tensions I1 which extend through bolt holes in the adjacent portion of the section I6A and receives nuts I8 to secure the housing sections together at the corresponding end of the housing.

The housing is preferably formed in three parts, as indicated above, for convenience in manufacture and assembly, but if found advantageous, can be provided in more or less parts, if desired, without in any way exceeding the scope of the invention. It is to be also understood that the number .of bolts securing the housing sections together is not limited to the four bolts I3 and I1, as shown in Figures 1A and 1B of the drawings.

The center section IIlC is provided with two cylindrical chambers I9 and 26 extending transversely therethrough in spaced apart and parallel relationship to each other and the end sections MA and I6B are provided with cylindrical recesses 2| and 22 in extension of the chamber I9 at the respectively opposite ends of the latter and cylindrical recesses 23 and 24 in extension of the chamber 26 at the respectively opposite ends of the latter chamber. The section I6A is also provided with hearing bores 25 and 26 ,extending from the recesses 2I and 23 respectively, eccentrically thereof, the bore 25 extending entirely through the section MA to the outer surface of the section and the bore 26 being a blind bore terminating short of the adjacent outer surface of the section IIlA of the housing.

The section I6B is provided with a bearing bore 21 extending from the recess 22 eccentrically of the latter and terminating short of the adjacent outer surface of the section. The section is further provided with a counterbore 26 constituting a pump chamber substantially coaxial of the bearing bore 21 and with a bore 21 of reduced diameter connecting the adjacent ends of the bore 21 and the pump chamber 26.

The pump chamber 26 extends to the outer surface of the section I6B and is closed at its outer end by a pump face plate 29 seated in an annular recess or groove at the outer end of the counterbore and secured to the outer face of the section MB in closing relationship to the outer end of the pump chamber by studs SI extending from the section I6B through apertures in the face plate 29 and nuts 32 threaded onto the studs at the outer side of the face plate.

A rotor shaft 33 extends eccentrically through the chamber I9 in the center housing section I6C and eccentrically through the recesses 2I and 22 in the housing end sections I6A and MB and through the bearing bores 25 and 21 in the end sections. This shaft is journaled in the bore 25 by a bearing bushing 34 of cylindrical shape disposed in a counterbored intermediate portion of the bore and is journaled in the bearing bore 21 by a bearing bushing 35 of cylindrical shape disposed in a counterbored intermediate portion of the bore 21.

An oil seal bushing 36 is mounted on the shaft at the end of the bearing bushing 34 nearest the recess 2I in the section WA and, while movable longitudinally of the shaft, is forced to rotate '4 with the shaft by a spline connection 31 between the oil seal bushing and the shaft. Packing rings 38 surround the shaft within the oil seal bushing 36 and a compression spring 39 surrounds the shaft between the end of the oil seal bushing 36 remote from the bearing bushing 34 and a spring abutment ring 46 which surrounds -the shaft and bears on an annular external flange 4I provided on the shaft, so that the spring holds the abutting end of the oil seal bearing 36 and bearing bushing 34 in sealing engagement with each other. An oil seal 42 is disposed in a counterbore in the outer end of the shaft bearing bore 25 and surrounds the shaft at the outer surface of the housing end section IDA. A drain channel 43 leads from the bore 26 at a location between the oil seals 36 and 42 .to the drain or sump of the transmission, so that any hydraulic fluid leaking through the seal 36 will be stopped by the low pressure seal 42 and returned to the sump of the transmission through the drain channel 43 provided in the housing section .IIIA. The shaft 33 extends outwardly of the oil seal 42 and the adjacent outer surface of the housing and is adapted to be connected at it outwardly extending end to a power source, such as the engine of an automotive vehicle, and constitutes the drive shaft of the transmission.

A rotor body 44 of cylindrical shape i disposed in the chamber I9 in the housing center section IOC and mounted on or formed integrally with the .shaft 33 concentrically of the shaft, and has a diameter less than the diameter of the chamber I9. The rotor body 44 is provided with a plurality of vane slots 45 which extend radially of the body at equally spaced angular intervals therearound and longitudinally of the body from one end to the other. Vanes 46 of substantially rectangular cross sectional shape are slidably mounted one in each of the vane slots 45 for movement radially of the rotor body 44 toward and away from the rotational axis of the shaft 33. Each vane slot is provided in the face at the rear thereof with reference to the rotational direction ,of the rotor body 44 with spaced apart grooves 41 extending radially of the rotor body, so that hydraulic fluid can pass freely between the inner and outer ends of the vane slots and will not be trapped in the inner ends of the slots to interfere with inward and outward movement of the corresponding vanes.

A governor block 46 ,of rectangular cross sectional shape is mounted in the space between the rotor body 44 and the wall of the chamber I9 at the bottom of the chamber and is longitudinally curved, so that its outer surface has a partly cylindrical curvature fitting the wall surface of the chamber I9 and its inner surface has a partly cylindrical curvature parallel to the curvature of the outer surface thereof, the axis of curvature of the inner and outer surfaces of the governor block 46 being the longitudinal axis of the chamber l9 and the recesses 2I and 22. The rotor body 44 i nearer the wall of the chamber I9 at the side of the chamber adjacent the chamber 26 than the side of the wall of the chamber I9 remote from the chamber 26 and the governor block 46 is movable to a limited extent around the wall of the chamber I9, the arrangement being such that when the governor block moves in a direction toward the chamber 26 or in a direction opposite the direction of rotation of the rotor body 44, it moves closer to the peripheral surface of the rotor body and when it moves in the opposite direction or in the same direction as the direction of rotation of the rotor body 44, it also moves away from the peripheral surface of the rotor body, so

that the effective area of the vanes 46 is de-.

creased when the governor block moves opposite to the direction of rotation of the rotor body 44 and is increased when the governor block moves in the same direction as the direction of rotation of the rotor body.

The governor block 48 is disposed between the lower side of the rotor body 44 and the lower side of the chamber I9 and grooves 49 are provided in the wall of the chamber I9 extending longitudinally of the governor block 48 for a purpose to be later described in detail. Slots 49' cut in the rear end of the governor block register respectively with the grooves 49.

A partition formation 53 extends from the wall surface of the chamber I9 to contact with the peripheral surface of the rotor body 44 at a location spaced from the front end of the governor block 43 with reference to the rotation direction of the rotor body 44 and at a location at which the vanes 46 are fully retracted relative to the peripheral surface of the rotor body and divides the space within the chamber I9 surrounding the rotor body 44 into two separate parts, as indicated at SI and 52.

A guide ring 53 of cylindrical shape is disposed in and substantially fills the recess 2| and this guide ring is provided with a centrally disposed bore 54 of a diameter greater than the diameter of the shaft 33, so that the guide ring 53 which is eccentric of the shaft 33, can move angularly relative to the shaft without binding. The guide ring 53 is provided with an annular groove 55 intermediate its length and an oil seal ring 56 is disposed in this groove and bears against the wall surface of the recess 2|. At the end of the guide ring 53 remote from the rotor body 44 the housing section I9A is provided with an annular groove 5! which is concentric with the recess 2I and has the same outside diameter as the diameter of the recess.

A cylindrical guide ring 58 is disposed in and substantially fills the cylindrical recess 22 and is somewhat longer than the guide ring 53. The guide ring 58 is provided with a centrally disposed bore 59 through which the shaft 33 extends and which has a diameter greater than the diameter of the shaft, so that the guide ring 58 can also move angularly of the shaft without binding. The guide ring 58 is provided near its outer end with an annular groove 69 receiving an oil seal ring 6! which bears against the wall surface of the recess 22 and is provided in its outer end with an annular, concentric groove 62 receiving an oil seal ring 63 which bears against the surface of the end wall of the recess 22. The guide ring 53 is also provided with a concentric annular groove 64 in its outer end and an oil seal ring 65 seated in the groove 64 and bearing against the surface of the end wall of the recess 2 I.

The housing section IOB is provided at the outer end of the recess 22 with an annular groove 65; concentric with the recess and having an outside diameter equal to the diameter of the recess, the purpose of the grooves 51 and 66 to be later explained in detail.

The governor block 48 is disposed between the guide rings 53 and 53 and secured at its respectively opposite ends to the mutually opposed end surfaces of these rings by suitable means, such 6, as the pins'IiI projecting from the ends of the governor block and received in recesses provided in the corresponding ends of the guide rings near the outer edges of the latter.

The guide ring 53 is provided in its inner end with an annular groove 68 which is concentric of the guide ring, and the guide ring 58 is provided in its inner end with a corresponding, concentric annular groove 69.

Sector shaped elements III are disposed in the groove 68 in side by side relationship, and together constitute a multi-part ring movable around the groove 68, there being one sector 10 for each vane 46 of the driving rotor and similar sectors II are mounted in the groove 69. Each vane 46 is connected at its respectively opposite ends to corresponding sectors ID and II by pins, as indicated at I2 and I3, projecting one from each end of the vane and received in apertures in the corresponding sectors I0 and II.

The grooves 68 and 69 are eccentric of the rotational axis of the rotor body 44, and, as the shaft 33 and rotor body 44 rotate about the rotational axis of the shaft 33, the sectors I0 and II are moved around the grooves 68 and 69, and the vanes are positively moved radially inwardly and outwardly of the rotor body as the rotor rotates.

The governor block 48 is so positioned around the chamber I9 and its inner surface is so curved that the outer ends of the vanes 45 engage the inner surface of the governor block as the vanes are moved past this block, and movement of the governor block around the cylindrical wall surface of the chamber I 9 brings the governor block to positions at which the vanes are protruded more or less from the rotor body 44, so that the effective vane area between the peripheral surface of the rotor body 44 and the inner surface of the governor block 48 is varied by movement of the governor block angularly of the cylindrical chamber I9.

The governor block 48 cooperates with the vanes 46 to provide the passage through which the hydraulic fluid is forced by the vanes from the space 52 at the inlet side of the pump passage to the space 5I which will normally constitute a high pressure space for the driving rotor.

The housing section 19B is provided with a second shaft bearing bore I5 extending from the end of the recess 24 remote from the chamber 20 to the adjacent outer surface of the section IOB and bearing bushings I6 and I! are mounted in the bores 23 and I5 respectively. A driven shaft I8 extends through the bores 26 and I5 and through the recesses 23 and 24 and the chamber 20 and is journaled in the bearing bushings I6 and I1 and this shaft projects outwardly of the outer surface of the housing section IQB and is adapted to be drivingly connected to driven means, such as the propeller shaft or differential unit of an automotive vehicle which propeller shaft or differential unit is connected, in turn,

to the traction wheels of the vehicle.

An oil seal bushing I9 surrounds the shaft I8 at the inner end of the bearing bushing 16 and is rotated by the shaft through a spline connection 80. Oil seal rings 8| surround the shaft I8 within the oil seal bushing I9 and a compression spring 82 surrounds the shaft between the end of the oil seal bushing 19 remote from the bearing bushing 16 and an annular spring abutment 83 supported on the shaft by an annular flange 84 on the shaft to hold the adjacent ends of the auras 1 bumings I8 and I9 in sealing engagement with each other. 7

An oil seal bushing 85 surround the shaft 18 at the inner end of a bearing bushing I1 and is drive'nly connected to the shaft by a spline connection 86. A compression spring 81 surrounds the shaft I8 between the end of the oil seal bushing 85 remote from the bearing bushing 11 and an annular spring abutment 88 supported on the shaft by an annular shoulder 88 on the shaft holds the abutting ends of the bushings 85 and II in sealing engagement, and oil seal rings 98 sin'round the shaft 18 within the oil seal bushing 35. An oil seal 8| is mounted in a counterbore at the outer end of the bore I and surrounds the shaft I8 at the surface of the housing section I8B from which the shaft projects, and the drain channel 43 and drilled holes 43' and 43" connect the bore I5 between the oil seals 85 and 9I and the closed end of the bore 28 to a sump or low pressure portion of the transmission, so that any hydraulic fluid leaking past the seal 85 will be returned to the transmission. Shaft bore 25 is also connected to the drain channel 43 by a drilled hole 43a.

A rotor body 93 of cylindrical shape is eccentrically disposed within the chamber 28 and mounted on or formed integrally with the shaft I8. This rotor body is provided with vane slots 84 extending radially and longitudinally thereof at substantially equal angular intervals therearound and each slot is provided in its rear wall with reference to the direction of rotation of the rotor body with spaced apart grooves 95 which extend from the inner to the outer edge of each slot to prevent hydraulic fluid from being trapped in the inner or bottom ends of the slots and interfering with movement of the corresponding vanes therein.

Vanes 96 of substantially rectangular shape are slidably mounted, one in each of the vane slots 94 and are movable radially toward and away from the rotational axis of the rotor body 83 in a manner to be presently described.

A guide ring 91 of cylindrical shape is received in and fills the recess 23 and a corresponding guide ring 98 i received in and fills the recess 24. The guide ring 91 is provided in its peripheral surface with an annular groove 99 and an oil seal ring I88 is mounted in this groove and bears against the cylindrical wall surface of the recess 23. This guide ring is also provided with an annular, concentric groove I8I in its end remote from the rotor body 93 and an oil seal ring I82 is received in the groove IN and bears against the surface of the end wall of the recess 23.

The guide ring 98 is provided in its peripheral surface with an annular groove I83 receiving a packing ring I84 bearing against the cylindrical wall surface of the recess 24 and in its end remote from the rotor body 93 with a concentric annular groove I85 receiving a packing ring I86 bearing against the end wall surface of the recess 24.

The housing section MA is provided with an annular groove I81 at the outer end of the recess 23 which groove is concentric with the adiacent recess and has an outside diameter substantially equal to the diameter of the recess, and the housing section I8B is provided with an annular groove I88 at the outer end of the recess 24 which is concentric with the recess 24 and has an outside diameter substantially equal to the diameter of this recess. The guide ring 81 has a central bore I88 larger than the shaft Ia and through which the shaft passes. and the guide ring 98 has a corresponding central bore I I8 for the shaft.

The rotor body 93 is disposed nearer the side of the chamber 28 adjacent the chamber l8 than the side of the chamber 28 remote from the chamber I9, and a governor block III is disposed in the chamber 28 at the side of the bottom of this chamber remote from the chamber I8 and is of rectangular cross sectional shape and iongitudinally curved, so that its outer or convex side has a partly cylindrical curvature fitting the cylindrical wall surface of the chamber 28 and its inner surface has a partly cylindrical concave curvature parallel to the curvature of its outer side, the axis of curvature of the outer and inner sides of the governor block I I I being the langitudinal axis of the chamber 28 and the recesses 23 and 24. The governor block III is secured at its respectively opposite ends to the guide rings 91 and 98 by pins II2 which project from the ends of the governor block and are received in recesses in the mutually opposed faces of the guide rings.

The guide ring 91 is provided in its end adiacent the rotor body 93 with a concentric annular groove H3 and the guide ring 88 is provided in its end adjacent the rotor body 83 with a corresponding concentric annular groove IIl. Sector shaped elements II5 are disposed in the groove H3 and corresponding sector shaped elements III; are disposed in the groove III, the elements in each groove being disposed in side by side relationship and movable as a ring around the corresponding groove.

Each vane 96 of the driven rotor is connected at its respectively opposite end to corresponding sectors H5 and H6 by pins, as indicated at I I1 and H8, projecting from the respectively opposite ends of the vanes and received in apertures provided in the corresponding sectors III and H6.

With this arrangement, as the rotor body 83 rotates in the chamber 28 the sectors III and H8 are carried around the grooves H3 and H4 and positively move the vanes 88 inwardly and outwardly of the rotor body 83 as this body roa es.

The governor body I II is angularly movable to a limited extent relative to the chamber 28 and is so arranged that when it moves in the directron of rotation of the rotor body 93 it moves further from the peripheral surface of the rotor body, and when it moves in a direction opposite the direction of rotation of the rotor body, it inoves closer to the peripheral surface of the lat- The center housing section IOC is provided with a partition formation I28 which extends across the space between the rotor :body 93 and the side wall surface of the chamber 28 at the side of the chamber 28 adjacent the chamber I8 into contact with the peripheral surface of the rotor body and divides the space between the rotor body and the chamber wall surface into two parts as indicated at m and m.

A channel I23 in the center housing section I8C connects the space part 5| between the rotor body 44 and the wall surface of the chamber I8 to the space part I2I between the rotor body 33 and the wall surface of the chamber 23 and the spaces 5| and I2I, and the channel I23 together collstltute n upper pressure space collectively designated by the numeral I28,

A channel I26 also provided in the center section IOC of the housing connects the part 52 of the space between the rotor body 44 and the wall surface of the chamber I9 with the part I22 of the space between the rotor body 93 and the wall surface of the chamber 20, and the space parts '52 and I22 and the channel I26 together constitute a lower pressure space, collectively designated'at I21.

The outer ends of the vanes 96 of the driven rotor contact the curved inner surface of' the governor block I I I and have an effective area between the inner surface of the governor block and the peripheral surface of the rotor body 93 for rotating the driven rotor.

With this arrangement, when the driving rotor is driven by the shaft 33, it pumps hydraulic fluid from the lower pressure space I26 into the upper pressure space I23, increasing the fluid pressure in the space I25 above the fluid pressure in the space I21, and this pressure differential acting upon the areas of the vanes 96 of the driven rotor between the driven rotor body 93 and the inner surface of the governor block III causes the driven rotor to rotate and turn the driven shaft 18.

A channel I28 extends through the center housing section IOC and includes a valve chamber I29 of cylindrical shape and a valve shaft I30 extends longitudinally through the valve chamber I29 and projects at one end from the housing section IOA, as indicated at I3I in Figure 9. Within the valve chamber I29 the shaft is provided with oppositely projecting valve vanes I32 which are spaced apart longitudinally of the valve shaft and received in grooves I33 provided in the valve chamber between spaced apart and substantially parallel partition formations I34 on the housing center section I00, which partition formations are disposed transversely of the valve chamber I29. The valve vanes carry fluid seals, as indicated at I35 and I36, at their outer ends which seals contact the surface of the valve chamber when the vanes are disposed transversely of the channel I28 to block off the channel, the ends of the vanes being out of contact with the walls of the valve chamber when the vanes are disposed longitudinally of the channel or passage I28, so that in this position of the valve, fluid can flow freely from the channel I23 to the channel I26.

When the valve shaft I30 is in one operative position the channel I 23 is connected to the channel I26 and hydraulic fluid pumped by the driving rotor merely recirculates from the upper pressure chamber part '52 of this rotor, and does not turn the driven rotor. When the valve shaft I 30 is disposed in its other operative position, the channel I28 is blocked and the fluid pumped by the driving rotor must pass through and turn the driven rotor before it can return to the inlet side of the driving rotor.

From the valve chamber I29 the valve shaft I30 extends through a bore I31 in the housing section IOA and is provided in this bore with a. bearing bushing I38 and a spring pressed oil seal I39, similar to the oil seals 36, 19 and 85 described above. A low pressure oil seal I40 is received in a counterbore at the outer end of the valve shaft bore I31 and a drain channel I4I leads from the bore I31 between the oil seals I39 and I40 to the drain channel 43 to return any oil leaking past the seal I39 to the low pressure portion or sump of the transmission.

It is contemplated that when the transmission is mounted in an automotive vehicle, the outer end of the valve shaft I30 will be connected to the accelerator pedal of the vehicle in a manner such that, when the accelerator pedal has been depressed to a predetermined extent it will rotate the valve shaft I3I to close this bypass valve and when the accelerator pedal is released the bypass valve will be automatically opened.

With the above described arrangement, when the driving rotor rotates and increases the pressure in the upper pressure space I 23 above the pressure in the lower pressure space I 26, this pressure differential will tend to move the governor block 48 of the driving rotor in a direction to decrease the effective vane area of the driving rotor and the governor block III of the driven rotor in a direction to increase the effective vane area of the driven rotor, so that the torque delivered by the driven rotor will tend to increase relative to the torque applied to the driving rotor and the speed of the driven rotor will tend to decrease relative to the speed of the driving rotor, and with an increasing torque load applied to the driven rotor the torque delivered by this rotor will increase. Suitable means are provided, however, for controlling the movement of the governor blocks so that they do not move freely in the above noted manner, but have a controlled movement which accurately proportions the increase in torque delivered by the driven rotor to the increase in the torque load applied to this rotor.

Reaction pistons I43 and I44, as illustrated in Figure 2A, are mounted on the outer end of the guide ring 58 and received in the annular groove 66, these pistons being sealed to the groove Wall surfaces by sealing rings I45 and I46, respectively. The pistons I43 and I44 are disposed at substantially diametrically opposite positions relative to the guide ring 58 and stop formations I41 and I48 on the housing section :IOB close the groove 66 at diametrically opposite positions around the groove and are disposed one adjacent the piston I43 and one adjacent the piston I 44 with the piston I43 disposed at the opposite side of the stop formation I 41 from the piston I44, and the piston I44 being disposed at the opposite side of the stop formation I48 from the piston I43.i A coiled compression spring I49 is disposed in the groove 66 between the piston I 43 and the stop formation I 41 and a similar spring I50 is disposed in the groove between the piston I48 and the stop formation I44.

Pistons not illustrated, corresponding tothe pistons I 43 and I44, are mounted on the guide rings 53 and disposed in the groove 51 at diametrically opposite positions around the groove, and stop formations, not illustrated, on the housing section IOA extend into and close the groove 51 at diametrically opposite positions therearound. Springs, also not illustrated, corresponding to the springs I40 and I50, are disposed in the groove 51 between the pistons on the guide ring 53 and the corresponding stop formations.

Fluid channels I5I extend through the upper portions of the housing sections 40A and IIiB at locations spaced outwardly from the closed ends of the recesses 2I and 23 and the recesses 22 and 24 respectively, and one of these channels is connected to the grooves 66 and I08 by ports I5Ia and I5Ib respectively, andto the upper pressure space channel I 23 by ports I5Ic and I5I The other channel I5I is connected to the 1 It! and to h channe I b simi no il st ted- .I'he po t it leads nto h groo 56 be w the piston, I43 and the stop. formation I41 and the corre po d g ort leads into h roove 51 a 11 W1 position to apply fluid pressure from the upper p essure space I23- to the piston I43 on guide ring 58 and the corresponding piston on guide ring 53 in a direction to counteract the mov ment of h governor block 48 induced by the pressure differential between the upper and lower pressure spaces I23 and I26.

Fluid channels 35I also extend longitudinally 0.1 the lower portion of the housing sections IIlA 861d B respectively, one between the grooves 51 and I! and the other between the grooves 66 and H18 at loca ons spaced ou wa d y f om th cl sed en s of the adja ent e esses II d 23 and 1. and 2, a d. one or t ese h nne s i connecteq .to the grooves 58 and I08 by ports $M and MI?! and to the lower pressure space channel I}! by ports I0 and 35 Id. The other channel I is, connected to grooves 51 and I01 and to the channel In by similar ports and the channels "I and associated ports are effective to apply fluid pressure from the lower pressure space I26 .0 piston I43 at the side of this piston remote from port I5Ia and to the equivalent side of the corresponding piston on guide ring 53, so that the pistons resisting movement of governor block 45 are subjected to the same fluid pressure differential as the governor block.

The effective area of the piston I43, and the corresponding piston, is less than the effective and area of the governor block 48 by a predetermined amount, so that there is still a residual force tending to move the governor block 48 in a vane area reducing direction.

A fluid channel 52 leads from a source of fluid at a regulated pressure, later to be described, through a port I520 to the space between the piston I and the stop formation I48 and through a similar port, not illustrated, to the space between the corresponding piston on guide ring- 58 and stop formation in groove 5]. The pressure of the fluid thus supplied is regulated by an addustab e ressure re ulatin al to a. valve such thfit the pressure exerted on the piston I nd t e c r esp ndin piston, e actly b lances the residual force tending to move the governor block when the overnor block has been m ed to a red termined amount i its a e area reducing direction.

The compression springs IE9, and I5Ii are not utilized in the ordinary operation of the transmission, but come into play only when the load on the driven shaft reaches the predetermined capacity of the transmission to stop the governor block at a predetermined position after it opens the relief passage 40 and permits the hydraulic fluid in the upper pressure space I23. to bypass into the lower pressur space I 6, to t eby limit the fluid pressure built up by the driving rotor to a saf value.

Pistons I53 and Ill p oject from the outer end of the guide ring 98 into the groove I08 at diametrically opposite positions around the guide rin and stop formations I55 nd I56. on th housin end section IIIB extend into the groove I". at diametrically opposite locations around the groove spaced from the locations of the. pistons I51 and I54. Compr s ion springs I5] and I58 are disposed. e etween the p ston I53 a d th at p formation I55. and the oth r. between the piston I54 and the stop formation I56, and the po t W ads f om the channel ml o t s a e, een t e pis 8 a h p ormation I55. The port 35Ib. leads into. groove 08 between 3 and stop formation I56 and the differential fluid pressure acting on the piston .53- resis movement of the governor block III in its vanes-res increasing direction, but the effective area of the piston I53 and its complementary piston on the guide ring 98 is less by a predetermined amount than the effective end area of the governor block III, so that a residual force is left tending to move the governor block in its vane area increasing direction.

Pistons, not illustrated. complementary to the pistons I53 nd I5! are provided on the guide rin 5 and. ex end int t r v I0 a o formations, not illustrated, on the housing section IIlA, complementary to the stop formation I55 and I55, extend into the groove I01 and close the groove. at diametrically spaced locations therearound. Compression springs, also not illustrated, complementary to the compression springs I58 and I59 are disposed between the corresponding pistons and stop formations in the grooves I01.

The port I52b leads from the channel I52 into the space between the piston I54 and the stop formation I55 and a corresponding port leads into the space between the piston on the guide ring 91 and the corresponding stop formation in the groove I01.

Channels I extend longitudinally of the housing sections "IA and I 03 adjacent and substantially parallel to the channels III and a port "Ila connects one of these channels into the groove 66 between piston I and stop I". A po t Iilb connects this same channel I into the. groove I08 between piston in and stop I55. Corresponding ports connect the other channel I60 into the grooves II and III at corresponding locations.

A cross channel I55 connects the channels IIII at the ends ofthese channels at the side of rotor chamber I9 remote from rotor chamber 20 and channels, later to be described, connect the cross channel I60 to a source of fluid at a regulated pr ssure to maintain a predetermined fluid pr sure acting against the reaction pistons in oppocinch to the same regulated fluid pressure applied to the, reaction pistons through channels in for a purpose to be later explained.

A pump ro r body Iii. is dispos d in the pump chamb r 28, nd mounted on a pump shaft I62 w h extends long tud nally from th y adjacent end of the. drive, 3.3. and is drivinsly oo nee ed at o e end. to t e dflv sh fte pump body I6 I is of cylindrical shape and has longitudmal y and adiall d posed vane slots I63 openms to the per her l su face thereof at substant ails equal. angula int r s r a und an va es Q64 slidaplymounted, one in each of the vane slots I63.

T e pump r tor I" is e ntr ally d selative o. t pump a ber 2! and a stop formation I, projects from the cylindrical wall of the pump chamber into contact with the peripheral surface of the pump rotor body IOI at a location around the rotor body at which the vanes I are fully retracted within the peripheral Surface f e or The pump face plate 18 is provided with an annular groove 29 in the face thereof adjacent the pump r t r and eoto s m are mounted in this groo e in side bye ationshi and extend around the groove in ring formation. The

groove 29 is eccentric relative to the rotational axis of the pump rotor body I6I and the pump vanes I64 are connected each to a sector I66 by suitable means, such as the pins I61 projecting one from each vane and engaged in an aperture in a corresponding sector. A circular groove 329 is provided in I8B at the side of pump chamber 28 opposite groove 29 and coaxial with the latter and apertured sectors 366 are disposed in groove 329 and receive pins I61 on vanes I64. With this arrangement, the vanes are positively moved inwardly and outwardly radially of the pump rotor body I6I as the rotor body is turned in the pump chamber 28.

The pump has an inlet space I68 extending from the stop formation I65 past a fluid inlet port I69 connected by a channel I10 to the drain channel 43, and a fluid outlet space I1I extending from the pump outlet channel I12 to the other side of the stop formation I65.

The pump outlet channel I12 is connected by fluid channels I13, I14 and I15 and the cross channel I16 to the channels I52.

A valve chamber I11 in the form of a cylindrical bore in the housing section IOB opens to one end surface of the housing section and has a screw threaded counterbore at its outer end receiving a screw plug I11. The screw plug I11 has a boss extending into the adjacent end of the valve chamber I11 and this boss is provided with an annular groove I18 connected by a channel I18 to the passage I15 and connected by angularly spaced apart fluid passages I19 to the inner end of a centrally disposed blind bore I80 in the plug I11 which bore extends through the boss having the groove I18 therein to the outer end of the boss.

A slide block I8I is slidably mounted in the valve chamber I11 and provided with longitudinally extending rack teeth I82, and a piston I83 extends from one end of the slide block I8I into the bore I80 in the plug I11.

At its end remote from the plug I11 the valve chamber I11 is provided with a second counterbore I84 and an abutment block I85 is slidably mounted in the counterbore I84 and has at one end cam following rollers I86 engaging a circumferentially extending cam surface I81 at the bottom of a groove formed in the peripheral surface of the guide ring 58.

A compression spring I88 is disposed between the slide block I8I and the abutment block I85 and held in position by spring guides I89 and I90 projecting from the slide block I8I and disposed within the hollow abutment block I85 respectively.

A valve chamber I9I in the form of a cylindrical bore in the housing section IOB is disposed adjacent and substantially perpendicular to the bore I11 and a valve I92 is rotatably mounted in the valve chamber I9I and provided at one end with a pinion gear I93, Figure 2A, the teeth of which mesh with the rack teeth I82 on the slide block or plunger I8I to rotate the valve body I92. A channel I14 leads from the channel I14 into the valve chamber HM and a channel I98 leads from the valve chamber I9I into a branch channel I95 which is connected by a channel I95 to the cross channel I60. I

At the location at which the channels I14 and I94 intersect the valve chamber I9I, the valve body I92 is provided with a vane formation I96 which controls the connection betweenthe passages I14' and I94.

The rotational position of the valve body I92 is controlled by movement of the slide block I8I from the pressure of the hydraulic fluid exerted on the outer end of the piston I83 compressing the spring I88, the force required to compress this spring being varied by movement of the abutment block I85 by the cam surface I81 on the guide ring 58, so that the pressure between the pump outlet channel I12 and the pressure regulating valve I92 is controlled by the strength of the spring I88 modified by the position of the cam surface I81 and this fluid pressure is such that when applied to the corresponding reaction pistons on the guide rings, it balances the residual pressure acting'on the rotor governor blocks at the particular positions of the governor blocks to hold the blocks against further movement by fluid pressure in the upper pressure chamber I25 until a change occurs in the load applied to the driven rotor or the power applied to the driving rotor.

A valve chamber I 91 in the form of a cylindrical bore is provided in the housing section IIIB at a location spaced from the bores I16 and I9I and this bore I91 is a blind bore closed at one end by the material of the section IDE and opening at its other end to the surface of the section IOB where it is closed by a screw plug I98 threaded into a screw threaded counterbore at the outer end of the bore I91. A valve piston I99 is slidably mounted in the bore I91 adjacent the inner end of the bore and a compression spring 208 is disposed in the bore I91 between the piston I99 and the screw plug I98. The piston I99 is provided with a central well or recess 20I in its end adjacent the inner end of the bore I91 and with radial ports 202 extending from the inner end of the recess 20I to the surface of the piston and the channel I leads at one end into the bore I91 at the closed end of the latter. At a location spaced from its inner closed end, the bore I91 is surrounded by a groove 203 and this groove is connected by perpendicularly disposed intersecting channels 204 and 205 with the drain channel 43. The channel 205 is also connected at one end into the valve chamber 91 between the piston I99 and the closure plug I98. Fluid pressure from the channel I95 acts on the piston I99 to force the piston against the spring 200 until the ports 202 register with the annular roove 203 to vent the fluid to the drain channel 43. The valve'piston I99 thus regulates the pressure of the fluid fed to the lower pressure space I21 and to the reaction pistons through th channels I60. 1

It is to be noted that between the bearing bushing 35 at the pump end of the shaft 33 and the rotor body 44 there is provided an oil seal bushing 201 driven by the shaft 33 through the spline connection 208 and pressed against the adjacent end of the bearing bushing 35 by a compression spring 209 which surrounds the shaft 33 between the end of the oil seal bushing 281 remote from the bearing bushing 35, and an annular spring abutment 2I0 supported on the shaft by an external annular flange or collar 2 on theshaft. With the structure sofar described, 'while the power source is driving the shaft 33 and the shaft 18 is driving the load, the driving rotor on the shaft 33 will increase the fluid pressure in the upper pressure space 25 relative to the fluid pressure in the lower pressure space I 21 and, with the clutch valve I30 closed, this pressure differential produced by the driving rotor will drive the driven rotor and the governor blocks of the driving and driven rotors will move, decreasing the som motive vane; area ofthedriving rotor; andiirrcreasing the eifectivevan'e area of the driven rotor until. the torque required at'thedrivemrotor is provided by the power 'supplicdtoither-drivin rotor and the two governor blocks will be held in proper position for each ratio. of power input to torque output'of the transmission; The trans mission will be maintained filled with hydraulic fluid and a predetermined minimum pressure maintained at all times in the lowerpressure space I21' to insure the maximum. efliciency of the driving, rotor.

Fluid pressure from'the: upper pressure-space is applied to one side-ofone of the reaction pistons on each guide ring and at thesame timc'. fluid pressure from the fluid pump outlet is appliedv to one face ofthe: other: piston on each guide ringconcurrentlywith the fluid pressure from'the' upper pressure space, so that the'force exertedby. fluid pressure on the-reaction pistons balances the force exerted bythe fluid pressurein the upper pressure space on'the governor block. Fluid at the pressure in. the lower pressure space I2iis also applied'to-the-sides of the reaction pistons opposite theysides'to which the upper fluid pressure space pressure and the pump Outlet pressure'are appliedand cancels-out when the driving: rotor is driving. the driven rotor;

The two governor:blocks! and III-are-connectedtogetherforslmultaneous and coextensive movement in respectively: opposite directions by gear meansmparticularly: illustrated in Figure 6: Each of the. guide rings provided with a series of peripheral gear teeth, as indicated at 218; M9; 228 andilli,for theguiderings 53; 58, 91 r and 9| respectively; and idler gears, as indicated at!!! and 223,2aremo1mtedin recesses-in the housing end members I8A- and IIIB, one pair between the guide rings-59and9l. and one pair between the guide-rings i8 and 98.- The idler gears 2land23 mounted'between theguide rings 58; andufl, asillustretedinF-igure mesh with eachsother and thezidler gear 222 meshes with the teeth 2il'ion'the guide ring. ",while the idler" gear 2231 meshes=with the gear teeth 228 on the :guide ring 91. The idlergear 222 is rotatably: mounted on a stud;- as indicated at 224, projecting :from thehousing end section I 9A and the idler gear 228:is:mounted on ons-end ofa shaft 225 which extends through the center section I86 and carriesv the corresponding: idler gear at the other side of the center section on its other end: The idler, gears-at the: opposite side of the center section are similarly mounted in recesses in the housingscction IOB and'one of them on a stud projectingfrom this housing section.

A feeder valve, generally indicated: at 228, is interposed between thegpressure relief valve I99 and the lower pressure space I21 to whichfluid is supplied at a pressure controlled by the relief valve I99.- This feeder valve comprises'a cylin' drical bore 229 in the housing. section IOB, opening to one face of'the housing: section and terminating. short of the opposite face of the latter, a valve pistonor plunger 230' slidably mounted in the bore 229,'and"acompression spring 2 9i" interposed between the valve" piston 230 and a. screw-plug-232 closing the outer open end or the bore-229. A groove fll extends' :lon'gitudinally of the bore-229 intermediate the length of the latterand'a spring pressed-detent flhis disposed in a transverse blindbore in the valve plunger 1 280 and-inns: its router end 'slidably receivediinthe. groove 2fl to1-hold :tbeplungenor Piston 298 against rotation in-the bore 229 con stituting" the valve chamber.

At its; end remote from the spring 23I the valve piston 239 is provided with acoaxial well 295- whichopens near its bottom to the cylindrioal surface of the piston, as indicated at 236, and-a channel-231 leads from the valve chamber atthe-location of the opening 236 to the channel I28: of the upper pressure space I25, so that thepressure of thehydraulic fluid in the upper pressure space I25isapplied to the feed valve piston 230 in a, direction to compress the associated'feed vaive spring 23I; The piston 230 has a valve port 239 extending transversely therethrough between the bottom or inner end of the well 235 andthe end of the piston engaged by the spring 23b and the housing section MB is provided with ports which register with the transverse valve port 239 when the valve spring 23I is compressed by fluid pressure in the upper pressurelspace I25, Channelsfli, 240' and 24 lead from the inlet port of the feeder valve 228 to one of the channels I connected to the pressure relief valve I99, as described above, and the channel 2311s" extended, as indicated at I, to connect thechannel I88 to the channel I22 through the transverse valve passage 239.

When the pressure in the upper pressure space I25 is below the pressure in channel I68 by a predetermined amount, the valve 228 opens, so that hydraulic fluid-will flow from the channel I6Ii into the upper pressure space I25. When the pressure in the upper-pressure space is above the pressure in channel I82, valve 228 closes, so that hydraulic-fluid cannot'escape from the upper pressure space thronghthe pressure relief valve I99.

All'oi' the mechanism necessary for'proper operation of the transmission when the shaft 38 is driving the shaft'18'has now been described, but additional mechanism is required when the torque is reversed. aswhen the vehicle in which the transmission-is mounted overruns the enduring deceleration of the vehicle or on a down-grade when the-gravity induced speed of the vehicle exceeds the engine speed.

Undera torque'reversal, as described above, the rotor 93 becomes the driving rotor, and the rotorltth'edriven rotor. so that thefiuid prasure in the lower pressure-space I21 will now exceed-the fluid pressure inthe upper pressure space I25; Upon areversal of pressure between the upper and lower-pressure-spaces the two govern'or blocks are urged ina direction to increase the effective vane area of the engine driven rotor. and'decreasethe effective vane area of the'wheel driving rotor. This permits the wheel driving rotorto rotate at a-speed higher than the rotational speed of the engine driven rotor, the pressure for driving the engine driven rotor being retained in thelower pressure space I2'I by a second feed valve'zls;

The second feeder valve 248 includes a cylindrical, blind bore 241 in the housing section IIIB preferably adjacent and'substantially parallel to the bore 229, the bore 2" also-being closed at one end by the material 01- the housing section IIIB and opening at its other end to the same face ofthe housinggection to which the bore 229 opens. A valve plunger or piston 248 is slidably mountedinthebore-N'I adjacent the closed end of this bore, and a compression spring 249 is disposed between the'piston 248 and ascrew plus lilclosins the-outcaopen end of the bore 17 241. The bore 241 is provided with a longitudinally extending groove 25I intermediate the length thereof and a spring pressed detent 252 mounted in a transverse aperture in the piston 248 has its outer end engaged in the groove 25I to hold the piston 248 against rotation in the bore 241. The piston 241 is provided in its end remote from the spring 249 with a coaxial well or recess 253 opening at its bottom or inner end to the side surface of the piston, as indicated at 254, and between the inner end of the recess 253 and the end thereof engaged bythe spring 249 the piston is provided with a transverse sage 255.

-A channel 256 leads through the channels 256' and 256" to the channel I26 of the lower pressure space I21 into the closed end of the bore 241 to apply the fluid pressure in the lower pressure space I21 to the piston 248 in a direction to compress the spring 249 and bring the passage 255 into registry with ports provided in the housing section IUB at diametrically opposite sides of the bore 241. A branch channel 356 leads from the channel 256' to the outlet port of the valve 246.

Channels 25?, 258 and 258' connect the inlet port of the valve 246 to one of the channels I68 to supply fluid at the pressure in channel I60 to the lower pressure space I21 when valve I46 is open. When the torque transmitted through the transmission is reversed, hydraulic fluid will be supplied at a pressure regulated by the pressure relief valve I99 to the upper pressure space I25 to insure that the transmission is filled with fluid at all times, and when the pressure in the lower space I21 exceeds the pressure in the upper space I 25, the feed valve 246 closes, so that the pressure in the lower space cannot then leak from the lower pressure space through the relief valve I99.

A rotatable valve, generally indicated at 260, is interposed between the pressure relief valve I92 and the line I16 conducting fluid from the outlet of the pump I H to the channels I52.

The valve 260 comprises a valve chamber 262 in the form of a cylindrical bore provided in the housing body I83 and having angularly spaced apart ports 263 and 264 leading to the channels I15 and I16, and a valve body 266 rotatably mounted in the chamber 262. At one end the valve body 266 is provided with a pinion 261 the teeth of which mesh with a rack 268 on the abutment block I85, so that movement of the abutment block I85 rotates the valve body 266 in the valve chamber 262. The valve body 266 has a fluid passage 269 extending transversely thereof which normally connects the ports 264 and 263.

The cam surface I81 in the guide ring 58 extends spirally of the peripheral surface of the guide ring and on a carefully calculated curve to maintain the balancing fluid pressure on the reaction pistons, as described above, when the engine driven rotor is driving the wheel driving rotor of the transmission. This cam surface is deeply recessed, as indicated at 210, at its end which engages the cam followers I86 when the torque is reversed between the wheel driving and engine driven rotors and the governor blocks are moved in the corresponding direction, as explained above. When the cam followers I86 ride into the deep or recessed end 210 of the camsurface I81, the abutment block I85 is moved to a limiting position and in this movement, rotates the valve body 266 until the valve body cuts off h port 264 from h port 263 and thereby cuts 18 oil the pump outlet pressure from the channels I 52 and the reaction pistons of the rotors.

The valve 260, in addition to the ports 263 and 264 connecting the channels I and I 16, has two additional ports, as indicated at 212 and 213, of which the port 213 is connected to the drain channel 43 by a channel 214.

A third pressure relief valve 280 is provided and comprises a valve chamber 28I in the form of a bore in the housing section IIlB opening to one end of the section and closed at its outer end by ascrew plug 282. At its end remote from the screw plug the chamber 28I has an extension 283 of reduced diameter connected at its closed end to the channel 243 leading from the valve port 212. A piston 284 is slidably mounted in the chamber 28I and has a reduced extension 285 received in the chamber extension 283. A compression spring 286 is disposed in the chamber 28I between the piston 284 and the screw plug 282 and the chamber and extension 283 are provided with longitudinally extending grooves 281 leading from the chamber extension 283 past the piston 284 in the chamber 28I and normally closed by the piston. A channel 288 leads from the valve chamber 28I to the drain channel 265 and connects the channel 243 to the drain channel 205 when the piston 284 is moved against the force of spring 286 sufficiently to uncover the portions of the grooves 281 in the chamber extension 283.

When a torque reversal through the transmission moves the governor blocks and turns the valve body 266 in the manner indicated above, the valve body cuts off the port 264 to discontinue application of fluid at the pressure regulated by pressure relief valve I92 to the reaction pistons through channels I52, but prior to closing port 264, opens port 212 to connect the channels I52 and the pump outlet to the pressure relief valve 280. If now the torque direction is restored by increasing the engine power, any fluid trapped in the reaction piston grooves in the spaces supplied by the regulated pump outlet pressure can escape through the relief valve 288 permitting the governor blocks to move back and the effective vane areas of the two rotors to change, so that the engine can pick up the load without stalling.

Continued closing movement of valve body 266 after opening port 212 opens port 213 and connects the spaces in the reaction piston grooves supplied with fluid at the regulated pump outlet pressure with drain to relieve the pressure in these spaces and render the entire pressure regulated by the pressure relief valve I99 effective to resist movement of the governor blocks in the reverse direction and thus insure transmission of a substantial reverse torque from the wheel driving to the engine driven rotor of the transmission. In addition to the springs, as indicated at I49, I50, I51 and I58, there are compression springs at the opposite sides of the corresponding reaction pistons or vanes, as indicated at 290, 29I, 292 and 293 in Figures 2A and 2B, which abut against the corresponding stop formations, as indicated at I41, I48, I55 and I56, when the governor blocks move to their extreme reverse position, and provide limit stops for the reaction pistons and for the governor blocks to cushion the stopping of the pistons and governor blocks when the governor blocks are driven to the extreme reverse position by a sufficient pressure differential between the lower and upper pressure spaces.

In the modified arrangement illustrated in Figures 11 to 14 inclusive, the construction is the same as that illustrated in the previous figures and described above, with the exception that the rotor vanes 46 and 96 are provided with longitudinally extending slots 300 in their outer ends and packing strips 3!" of suitable flexible and resilient material are mounted one in each of these grooves and bear against the inner surfaces of the corresponding governor blocks to provide fluid seals between the vanes and the governor blocks.

In this arrangement each governor block, instead of being of generally rectangular shape, as described above, is a complete hollow cylinder, as indicated at 302, eccentrically surrounding the associated rotor body 33 within the corresponding chamber and has circumferentially extending slots 303 therein spaced apart longitudinally thereof, the inner surface of the cylinder portions between adjacent slots as well as the inner surface portion of the cylinder between the ends of the slots providing tracks or guideways on which the packing strips 301 ride as the rotor body rotates in the governor cylinder. While the number of slots in the governor cylinder may be varied, four equally spaced apart slots each having a width substantially equal to one eighth of the length of the cylinder is considered to provide a satisfactory arrangement.

With the above described construction of the governor block, it is not possible to assemble the device if the partition formations, such as the formation I20 of Figure 3B, are made integral with the center housing section NC.

The partition formations are, therefore, omitted from the center housing section and this housing section is provided with socket recesses 304 opening one into each of the governor cylinder slots 303. The partition formation is then provided as a plurality of separate blocks 305 of rectangular cross sectional shape having a. thickness substantially equal to the width of the slots 303 and having at one end a boss received in the corresponding socket recess 304. The partition blocks 305 are disposed one in each slot 303 and each has a concave end surface 300 bearing against the peripheral surface of the associated rotor body and recesses 301 of elongated rectangular shape provided one in each side thereof and each receiving a packing element 303 which packing elements bear against the side wall surfaces of the slots 303 to provide fluid seals between the partition blocks and the governor cylinders.

The housing section is provided with a transverse bore extending through the socket recesses 304 and the bosses on the blocks are provided each with a transverse aperture 300 registering with the bore in the center housing section, and a locking pin 3l0 extends through the bore in the housing section and the apertures in the block bosses to lock the bosses in the socket recesses 304.

As the governor blocks will have a smaller effective end area when the vane packing seals are used, the reaction piston grooves will be much 20 and range of equivalency of the claims are, therefore, intended to be embraced therein.

What is claimed is:

1. A hydraulic transmission comprising a housin having spaced apart cylindrical chambers, shaft bearing openings, valve chambers and fluid passages therein, shafts journaled in said shaft bearing openings and extending eccentrically one through each of said chambers, said shafts projecting beyond said housing and being adapted for connection one to a power source and the other to driven means, cylindrical driving and driven rotors disposed one on each of said shafts coaxially thereof and received in the corresponding chambers, each of such rotors having a diameter less than the diameter of the correspondin chamber and angularly spaced apart and radially disposed vane slots therein, vanes slidably mounted one in each of said slots and projecting from the peripheral surface of the corresponding rotor, guide rings of cylindrical shape journaled in said chambers one at each narrower and the reaction pistons will have a end of each rotor and rotatably receiving the corresponding shafts, each of said guide rings having in its end adjacent the corresponding rotor an annular groove concentric with the corresponding chamber and said housing having annular grooves disposed one at each end of each chamber and concentric with the corresponding chambers, sectors slidably mounted in the grooves in said guide rings for movement around the corresponding annular grooves, means connecting each vane to two sectors disposed one at each end of the vane for movement of said vanes outwardly and inwardly of the corresponding rotors as said rotors rotate in the corresponding chambers, longitudinally curved governor blocks slidably mounted one in each chamber between the correspondin rotor and the chamber wall and connected each at its opposite ends to the corresponding guide rings, each of said governor blocks having its outer surface in contact with the wall of the corresponding chamber and its inner surface spaced from the peripheral surface of the corresponding rotor and being movable toward and away from the adjacent rotor surface upon angular movement of the associated guide rings in the chamber to maintain the inner surfaces of the governor blocks in engagement with the outer ends of the corresponding vanes at different amounts of effective vane area projecting beyond the peripheral surfaces of the corresponding rotors, partition formations on said housing projecting one into each of said chambers to the peripheral surfaces of the corresponding rotors at locations at which the rotor vanes are fully retracted within the peripheral surfaces of said rotors and together with said governor blocks dividing the space within each chamber surrounding the corresponding rotor into two separate portions, one of the fluid channels in said housing connecting the space portion in one of said chambers between the rear end of the corresponding governor block in the direction of rotation of the corresponding rotor and the associated partition formation to the space portion in the other of said chambers between the forward end of the corresponding governor block in the direction of rotation of the corresponding rotor and the associated partition formation, and constituting such space portions and channel an upper pressure space,and another of the channels in said housing connecting the other space portions in said chambers and providing a lower pressure space, said governor blocks being mov- 21 able to a limited extent around the corresponding rotors upon a rise in fluid pressure in said upper pressure space above the fluid pressure in said lower pressure space to simultaneously decrease the effective vane area of said driving rotor and increase the eifective vane area of said driven rotor, one of the valve chambers in said housing connecting said upper and lower pressure space channels to provide a bypass for said driving rotor, a manually movable valve in said valve chamber effective to close said chamber and force the fluid to pass from said upper pressure space around said driven rotor to said lower pressure space and constrain said driven rotor to rotate in response to rotation of said driving rotor, angularly spaced apart pistons on each guide ring at the ends of the guide rings remote from said rotors and received in the adjacent annular grooves in said housing, stop formations on said housing intercepting said annular grooves between the angularly spaced apart pistons in each groove, some of the fluid channels in said housing connecting said upper pressure space to the annular grooves in said housing in a manner to apply fluid pressure to one piston in each annular V housing groove in opposition to the application of fluid pressure to the ends of said governor blocks within said upper pressure space, the effective areas of said pistons being less than the eifective areas of the ends of said governor blocks by a predetermined amount, gear means in said housing interconnecting said governor blocks for simultaneous and coextensive movement in opposite directions, a fluid pump in said housing, some of the fluid channel in said housing connecting said pump to the annular grooves in said housing in a manner to apply pump pressure to the other piston in each annular groove to balance the difference in effective pressure of the fluid in said upper pressure space on said governor blocks and said pistons to hold said governor blocks in adjusted position and the corresponding chambers against further movement by the effect of fluid pressure on the differential areas of said pistons and said governor blocks, a first adjustable pressure regulating valve connected to the outlet of said pump to maintain a predetermined adjusted pressure at said pump outlet, a cam surface on one of said guide rings controlling said first pressure regulating valve, one of the channels in said housing connecting the outlet of said first pressure regulating valve to said lower pressure space, a second pressure regulating valve connected at its inlet to the outlet of said first pressure regulating valve to maintain a predetermined pressure on the fluid conducted to said lower pressure space and connected at its outlet to the inlet of said pump, and a body of hydraulic fluid in said housing.

2. A hydraulic transmission comprising a housing having spaced apart and substantially parallel rotor chambers of cylindrical shape therein, a drive shaft extending eocentrically through one of said chambers and journaled in said housing, a driven shaft extending eccentrically through the other of said chambers and journaled in said housing, rotor bodies disposed one on each shaft within and eccentric of the corresponding chambers, each of said rotor bodies having its ends spaced from the ends of the corresponding chambers and having longitudinally extending and radially disposed vane slots therein, vanes slidably mounted one in each of said vane slots for movement toward and away '=from the rotational axis of the corresponding shaft,

governor blocks disposed one in each rotor chamher and each having .a longitudinally convex outer surface contacting the associated chamber wall and a longitudinally concave inner surface spaced from the peripheral surface of the associated rotor body and engaged by the outer ends of the corresponding vanes as the vanes are moved thereby by rotation of the corresponding rotor body and shaft, said governor blocks being angularly movable in said chambers and toward and away from the peripheral surfaces of the corresponding rotor bodies upon angular movement of the governor blocks to vary the effective vane area of said rotor bodies, guide rings angularly movable in said chambers one at each end of each rotor body and filling the corresponding end portions of said chambers, means connecting each governor block to the guide rings adjacent thereto, each of said guide rings having in its end adjacent the corresponding rotor body a circular groove eccentric of the rotational axis of the rotor body, means movable around said grooves and connected to the adjacent vanes positively moving the vanes inwardly and outwardly of the corresponding rotor bodies as the rotor bodies rotate relative to the guide rings, partition formations disposed in each of said chambers and extending between the corresponding guide rings and from the corresponding chamber wall to the peripheral surface of the associated rotor body at a location spaced from the corresponding governor block and at which the vanes are fully retracted within the peripheral surface of the rotor body, each partition formation dividing the space within the corresponding chamber surrounding the corresponding rotor body into an inlet space and an outlet space and said housing having channels therein one of which connects the outlet space in said one chamber to the inlet space in said other chamber and constitutes an upper pressure space and the other of which connects the inlet space in said one chamber to the outlet space in said other chamber and constitutes a low pressure space, said housing also having a cross channel therein interconnecting said upper and lower pressure spaces to bypass said one chamber, a manually operated valve in said cross channel which when closed constrains hydraulic fluid flowing from the outlet to the inlet of said one chamber to flow from the inlet to the outlet of said other chamber and rotates said other rotor body, said governor blocks being urged by the fluid pressure differential between said upper and lower pressure spaces to move in a direction to decrease the eifective vane area of said one rotor body and increase the eflfective vane area of said other rotor body, and fluid pressure responsive means connected to said guide rings resisting movement of said governor blocks, said housing having relief channels therein in the walls of said chambers and said governor blocks having slots in the rear ends thereof which register with said relief channels when said governor blocks have been moved to predetermined positions in the corresponding chambers to limit the maximum fluid pressure in said chambers to a predetermined value.

3. A hydraulic transmission comprising a housing having spaced apart and substantially parallel rotor chambers of cylindrical shape therein, a, drive shaft extending eocentrically through one of said chambers and journaled in said housing, a driven shaft extending eocentrically through the other of said chambers and journaled in said 

